Printed circuit board assemblies (PCBAs) are used in numerous equipment including computers, telephones, major appliances, vehicles such as automobiles, trains, and planes, and toys, etc. The printed circuit boards (PCBs) are getting more crowded with items such as integrated circuits, resistors, heat sinks, and other components.
A series of processes is required to create the printed circuit board and add the components to the printed circuit board to create the completed printed circuit board assembly. Unfortunately the printed circuit board assembly manufacturing process does not result in each of the printed circuit board assemblies working perfectly. The components and the printed circuit board, while not expensive individually, together produce an expensive item. In addition, there is a time and cost factor in determining which printed circuit board assembly (PCBA) works properly and which PCBA does not work properly. In some situations, the cost and time involved in detecting non-functioning PCBAs is not acceptable, therefore requiring that the through-put of quality PCBAs be nearly 100%.
One type of failure in the printed circuit board assembly is strain-induced failure. Strain-induced failures can be created by various factors. These strain-induced failures include cracked BGA (ball grid array) solder joints, intermittent opens of conductive traces and joints, cracked printed circuit boards (PCB), and cracked capacitors. One method of determining what caused the strain is to affix strain gages to the printed circuit board. The strain gage has a series of wires connected to the strain gage on the circuit board which extend to instrumentation that monitors the strain on the printed circuit board.